Coffee machine



FIG. 1 is a front perspective;

FIG. 2 is a left side perspective;

FIG. 3 is a right side perspective;

FIG. 4 is a top view;

FIG. 5 is a bottom view; and,

FIG. 6 is a rear perspective.

The portions of the coffee machine that are not shown in the drawings do not form part of the claimed design. 

The ornamental design for a coffee machine, as shown and described. 